214 Progress of Foreign Science. 
with potassium, M. Berzelius fused in a small retort 0.782 grains 
of carbonate of potash with 1.5 grains of sulphur, and the 
mixture was exposed to a moderate heat until the.excess of 
sulphur was driven off. It weighed then 1.267 gr. To the upper 
part of the retort there was attached a small portion of hepar of 
a livelier red, which, on solution in water, deposited sulphur. It 
was, however, in so small quantity, that its weight was not ascer- 
tained. The salt employed contained 0.5326 grains of potash, of 
which 1=0.13315 had formed sulphate of potash=0.0458 grains 
of sulphur, and with the oxygen of the other 3. To find the quan- 
tity of sulphur that was combined with the reduced potassium, 
we must deduct from 1.267, the weight of the potash, and that 
of the sulphur in the sulphuric acid, together = 0.5784. This 
quantity is 0.6886, which was united to 0.3315 grains of potas- 
sium ; that is to say, 100 parts of potassium had taken 207.7 
parts of sulphur; but this number constitutes nearly 10 atoms; 
for the weight of K : 108 :: 100 ; 205.2. 
Hence, 100 parts of sub-carbonate of potash absorb at a maav- 
mum 93.9 of sulphur. The brighter colour of the hepar which 
was deposited on the upper part of the retort, and which, on 
solution, gave up sulphur, led to the belief that there existed a 
sulphuret of a still higher degree, which could not exist at a 
red heat, and which water also decomposed in separating a 
portion of its sulphur. But experiment shewed it to be merely 
a mixture of hepar and sulphur. 
3. It has already been observed, that when the sulphate of 
potash is decomposed, at a high temperature, by sulphuretted 
hydrogen gas, there results a bright hepar, entirely transparent, 
and of an orange red, which seems to be KS7; and when the 
same salt is decomposed by sulphuret of carbon, then is formed 
KS8. The latter is not transparent, and its colour is less beau- 
tiful than that of the preceding. There is observed almost always 
in these operations, the same proportion of sulphur in excess. 
4, By varying the proportions, M. Berzelius obtained sulphu- 
rets which he regards as compounds of 2, 4,6, 7, 8, 9, and 10 
atoms of sulphur with | of potassium. 
1. KS? is obtained by reducing sulphate of potash, by means 
of hydrogen. 
2. KS* by fusing carbonate of potash at a red heat, with a 
quantity of sulphur less than is necessary to decompose it. 
3. KS6 ; by heating slowly the said mixture, till it melts with- 
out ebullition or the disengagement of any gas whatever. 
4. KS’; by reducing the sulphate of potash, with sulphu- 
retted hydrogen gas. 
5. KS® ; by keeping in fusion the hepar at the maximum 
either water of sulphur be disengaged ; or otherwise, by re- 
ducing sulphate of potash, by sulphuret of carbon. 
